1. Field of the Invention
This invention is generally related to receptacles formed by sectional components, and is specifically related to receptacles for housing electrical or electronic circuitry for apparatus such as communications equipment and the like.
2. Background and Prior Art
Housings for communications equipment such as mobile telephones and the like must not only physically protect the electronic circuitry of such apparatus, but must also shield the internal circuitry from electromagnetic interference (EMI) which comes from the surrounding environment, and must shield individual electronic components from radio-frequency interference (RFI) which is produced by other components of the equipment itself. Interference from EMI and RFI causes degradation in the performance of high-frequency circuitry, and thus it is necessary to electromagnetically isolate the circuitry components as much as possible from EMI and RFI. Gaskets made of electrically conductive materials, commonly known as shielding gaskets, may typically be used around the external edges of mating elements of the housing to isolate the circuitry from EMI. Shielding gaskets may also be used inside the housing to isolate sensitive circuitry such as high-frequency modulating or demodulating circuitry, from RFI produced by other nearby circuitry within the housing. This is typically accomplished by using internal dividing walls that compress the shielding gaskets against grounding trace lines on a printed circuit board to form closed electromagnetic barriers between different sections of the circuit board.
Prior constructions for such housings are known in the art; see, e.g., U.S. Pat. Nos. 3,450,293 and 4,711,361. Such constructions are characterized as being fully interlocking. That is, the separate elements of the housing are fully interlocked by sliding the mating parts of the elements with respect to each so that when the elements are aligned, they cannot be separated except by sliding in the same manner. Such fully interlocking joints had the advantage of being applicable to housings of constant cross section, making it possible to produce the housing elements by extrusion rather than by die casting, and thus reducing tooling cost and development time.
However, such fully interlocking constructions as exemplified by the above referenced patents are not well suited for equipment where internal electromagnetic shielding is required. This is because sliding the mating parts of the housing elements together may damage the shielding gaskets or dislocate the gaskets from their intended alignment within the housing. Thus, internal dividing walls employing shielding gaskets could not be used in these constructions. Fully interlocking constructions were also difficult and time consuming to assemble, requiring precise end-to-end alignment prior to sliding the mating elements together. Additionally, such prior constructions had a tendency to bind up during assembly from misalignment, warpage, or surface roughness.
Consequently, there exists a need in the art to provide a housing construction having mating elements which can be easily assembled and disassembled to facilitate the use of electromagnetic shielding gaskets for sensitive electronic circuitry enclosed within the housing.